IACR News
Here you can see all recent updates to the IACR webpage. These updates are also available:
12 January 2024
Estuardo Alpírez Bock, Chris Brzuska, Pihla Karanko, Sabine Oechsner, Kirthivaasan Puniamurthy
Sedigheh Khajouei-Nejad, Sam Jabbehdari, Hamid Haj Seyyed Javadi, Seyed Mohammad Hossein Moattar
Jan Bobolz, Jesus Diaz, Markulf Kohlweiss
Current AC and GS variants reach specific points in the privacy-utility tradeoff, which we point as counter-productive engineering-wise, as it requires full and error-prone re-engineering to adjust the tradeoff. Also, so far, GS and AC have been studied separately by theoretical research.
We take the first steps toward unifying and generalizing both domains, with the goal of bringing their benefits to practice, in a flexible way. We give a common model capturing their core properties, and use functional placeholders to subsume intermediate instantiations of the privacy-utility tradeoff under the same model. To prove its flexibility, we show how concrete variants of GS, AC (and others, like ring signatures) can be seen as special cases of our scheme – to which we refer as universal anonymous signatures (UAS). In practice, this means that instantiations following our construction can be configured to behave as variant X of a GS scheme, or as variant Y of an AC scheme, by tweaking a few functions.
Aikata Aikata, Dhiman Saha, Sujoy Sinha Roy
10 January 2024
Fortanix
Fortanix is a dynamic start-up solving some of the world’s most demanding data protection challenges for companies and governments around the world. Our disruptive technology maintains data privacy across its entire lifecycle -- at rest, in motion, and in use across any enterprise IT infrastructure -- public cloud, on-premise, hybrid cloud, and SaaS.
Fortanix is looking for a Sr. Software Engineer, Cryptography with software development experience.
In this role, you will:- Implement and maintain production-ready cryptography code in Rust and C/C++, including new algorithms and secure cryptography APIs
- Analyze state-of-the-art attacks and implement side-channel mitigations
- Participate in peer code review, educate
- Write, research
- Help deploy, monitor, and tune the performance of our software
- Analyze existing designs
You have:
- Uncompromising integrity
- Outstanding attention to detail
- Critical thinking about complex technical problems
- Proactive and independent, while also being a team player
- Programming experience in Rust, C/C++
- A Master's or PhD in Cryptography or a related field, or equivalent training or work experience
- You currently reside in the EU and have a valid EU work permit
Closing date for applications:
Contact:
Francisco José Vial-Prado
(francisco.vialprado@fortanix.com)
More information: https://jobs.workable.com/view/3HZKGKSmAcrrj6Uetp5Wdd/senior-software-engineer%2C-cryptography-in-eindhoven-at-fortanix
Hongrui Cui, Hanlin Liu, Di Yan, Kang Yang, Yu Yu, Kaiyi Zhang
Manuel Barbosa, Deirdre Connolly, João Diogo Duarte, Aaron Kaiser, Peter Schwabe, Karoline Varner, Bas Westerbaan
Walid Haddaji, Loubna Ghammam, Nadia El Mrabet, Leila Ben Abdelghani
Damien Robert, Nicolas Sarkis
Jian Wang, Weiqiong Cao, Hua Chen, Haoyuan Li
Tore Kasper Frederiksen, Jonas Lindstrøm, Mikkel Wienberg Madsen, Anne Dorte Spangsberg
István András Seres, Péter Burcsi, Péter Kutas
However, there are various roadblocks to making class groups widespread in practical cryptographic deployments. We initiate the rigorous study of hashing into class groups. Specifically, we want to sample a uniformly distributed group element in a class group such that nobody knows its discrete logarithm with respect to any public parameter. We point out several flawed algorithms in numerous publicly available class group libraries. We further illustrate the insecurity of these hash functions by showing concrete attacks against cryptographic protocols, i.e., verifiable delay functions, if they were deployed with one of those broken hash-to-class group functions. We propose two families of cryptographically secure hash functions into class groups. We implement these constructions and evaluate their performance. We release our implementation as an open-source library.
Xin Xiangjun, Qiu Shujing, Li Chaoyang, Li Fagen
Shahla Atapoor, Karim Baghery, Hilder V. L. Pereira, Jannik Spiessens
Yi-Hsiu Chen, Yehuda Lindell
09 January 2024
Goethe University Frankfurt
To strengthen our team, we are looking for committed, creative, and flexible scientific employees with in-depth expertise in the field of computer science, as well as an interest in current developments in business informatics. The environment of mobile systems or applications will provide you with valuable work experience in an interdisciplinary project involving travel and project responsibility, such as the BMBF project 'FIIPS@Home' (engl. ‘Early warning, information, and intrusion prevention system for the security of private home networks’).
We offer an interesting and varied range of tasks with the opportunity to contribute your own creative ideas. Goethe University Frankfurt is a family-friendly employer with flexible working time models, its own collective labour agreement and a free Hessen State public transport ticket.
If you are interested, please visit https://m-chair.de/career for full details. Application is open until January 30, 2024
Closing date for applications:
Contact: bewerbungen@m-chair.de
More information: https://m-chair.de/images/documents/career/20240103WissMA_eng.PDF
08 January 2024
Thomas Debris-Alazard, Pouria Fallahpour, Damien Stehlé
Our main result is a quantum polynomial-time algorithm that samples well-distributed $\mathsf{LWE}$ instances while provably not knowing the solution, under the assumption that $\mathsf{LWE}$ is hard. Moreover, the approach works for a vast range of $\mathsf{LWE}$ parametrizations, including those used in the above-mentioned SNARKs.
Aarav Varshney, Prashant Agrawal, Mahabir Prasad Jhanwar
Hoeteck Wee, David J. Wu
In this work, we develop two (non-interactive) functional commitments that support fast verification. The first construction supports openings to constant-degree polynomials and has a shorter CRS for a broad range of settings compared to previous constructions. Our second construction is a dual functional commitment for arbitrary bounded-depth Boolean circuits. Both schemes are lattice-based and avoid non-black-box use of cryptographic primitives or lattice sampling algorithms. Security of both constructions rely on the $\ell$-succinct short integer solutions (SIS) assumption, a falsifiable $q$-type generalization of the SIS assumption (Preprint 2023).
In addition, we study the challenges of extending lattice-based functional commitments to extractable functional commitments, a notion that is equivalent to succinct non-interactive arguments (when considering openings to quadratic relations). We describe a general methodology that heuristically breaks the extractability of our construction and provides evidence for the implausibility of the knowledge $k$-$R$-$\mathsf{ISIS}$ assumption of Albrecht et al. (CRYPTO 2022) that was used in several constructions of lattice-based succinct arguments. If we additionally assume hardness of the standard inhomogeneous SIS assumption, we obtain a direct attack on a variant of the extractable linear functional commitment of Albrecht et al.
Hongxiao Wang, Siu-Ming Yiu, Yanmin Zhao, Zoe L. Jiang
A major difficulty in constructing a $\textit{non-black-box}$ lattice-based MVC is that it is not trivial to construct a lattice-based VC that satisfies a critical property called ``mercurial hiding". In this paper, we identify some specific features of a new falsifiable family of basis-augmented SIS assumption ($\mathsf{BASIS}$) proposed by Wee and Wu (EUROCRYPT '23) that can be utilized to construct the mercurial vector commitment from lattice $\textit{satisfying}$ updatability and aggregatability with $\textit{smaller}$ auxiliary information. We $\textit{first}$ extend stateless update and differential update to the mercurial vector commitment and define a $\textit{new}$ property, named updatable mercurial hiding. Then, we show how to modify our constructions to obtain the updatable mercurial vector commitment that satisfies these properties. To aggregate the openings, our constructions perfectly inherit the ability to aggregate in the $\mathsf{BASIS}$ assumption, which can break the limitation of $\textit{weak}$ binding in the current aggregatable MVCs. In the end, we show that our constructions can be used to build the various kinds of lattice-based ZKS and ZK-EDB directly within the existing framework.